Hello everybody!!!!!!!!!
How could make a programm which will measure the pressure of atmosphere????
i have the 1115 sensor about phidget and i don't know how make a routine about pressure......... 
To start with, wire the appropriate connections on the phidget up to 5V, ground and an analog pin on the arduino. Use analogRead to get a reading and display it using serial.println. Then you can figure out how to transform the voltage you're getting into the units of your choice with a little math.